3-Azawurtzitan und 3(4 → 5)abeo-3-Azawurtzitan

3-Azawurtzitane and 3(4 → 5)abeo-3-Azawurtzitane 3-Azawurtzitane (14) and 3(4 → 5)abeo-3-azawurtzitane (15) as well as derivatives thereof are described. The known tricyclic unsaturated ketone 1 was transformed to the properly functionalized endo-amines 3, 5 and 12. Entry to the azawurtzitane system and its corresponding abeo-compounds was achieved by three different cyclization procedures: aminomercuration with mercuric acetate in water (3 → 14, 5 → 16) , olefin amination with mercuric acetate in dimethyl sulfoxide (3 → 18, 5 → 20 + 21) and intramolecular attack at an epoxide (12 → 24 + 25). Molecular rearrangements of 3-azawurtzitanes to 3(4 → 5)abeo-3-azawurtzitanes and vice versa are described involving neighbouring group participation of the N (3) atom.     

Echanges isotopiques d'hydrogène T-H,T-D,D-H et H-D de la diazoacétone et du diazoacétaldéhyde: Vitesse de protonation et effets isotopiques. Communication préliminaire

The velocities of four acid-catalysed hydrogen isotope exchange reactions between diazoacetone ( 1 ) and water (T → H, T → D, D → H, and H → D) and of three exchange reactions between diazoacetaldehyde ( 2 ) and water (T → H, T → D, and H → D) have been measured. The exchange D → H of 1 was found to be submit to general acid catalysis (α_B = 0.6). The rates of protonation of primary and secondary diazocarbonyl compounds of similar structure were found to be quite similar, in spite of difference in mecanism (A-2 and A-S_E2, respectively).     

Catalytic Intramolecular Palladium-Ene Reactions. Preliminay Communication

Pd(dba)₂[dba = dibenzylideneacetone]/PPh₃-or Pd(PPh₃)₄-catalyzed cyclizations of acetoxy-dienes 2 → 3 and 10 → 11 gave 1-vinyl-2-methylidene-subsituted cyclopentances and cyclohexanes in high yield, consistent with a palladium-ene/β-elimination mechanism ( D → E → F , Scheme 2). The efficient and highly stereoselective cyclizations 7 → 7 and 8 → 9 illustrate intramolecular allylpalladium insertions into 1,2-dialkyl-, trialkyl-, trialkyl-, and cyclic alkenes followed by elimination of the exocyclic β–H giving 1,2-divinylcyclopentanes. These new olefin insertions proceed faster in AcOH (compared to THF) and occur preferentially cis relative to the Pd ( 13 → 14 → 15 ).     

Anatoliosides: Five Novel Acyclic Monoterpene Glylcosides from Viburnum orientale

Five new acyclic monoterpene glycosides 1 – 5 were isolated from the leaves of Viburnum orientale (Caprifoliaceae). Anatolioside ( 1 ) is a monoterpene diglycoside and its structure was elucidated as linalo-6-yl 2′-O-(α-L -rhamnopyranosyl)β-D -glucopyranoside (arbitrary numbering of linalool moiety). Compounds 2 – 5 are all derivatives of 1 , containing additional monoterpene and sugar units, connected by ester and glycoside bonds. Their structures were established as linalo-6-yl O-[(2E,6R)-6-hydroxy-2, 6-dimethylocta-2,7-dienoyl]-(1? → 4″)-O-α-L -rhamnopyranosyl-(1″? → 2″″)-β-D -glucopyranoside ( = anatolioside A; 2 ), linalo-6-yl O-β-D -glucopyranosyl-(1? → 6?)-O-[(2E,6R)-6-hydroxy-2,6-dimethylocta-2,7-dienoyl]-(1? → 4″)-O-α-L -rhamnopyranosyl-(1″ → 2′)–β-D -glucopyranoside ( = anatolioside B; 3 ), linalo-6-yl O-β-D ribo-hexopyranos-3-ulosyl-(1′? → 6?)-O-[(2E,6R)-6-hydroxy-2,6-dimethylocta-2,7-dienoyl]-(1? → 4″)-O-α-L -rhamnopyranosyl-(1″ → 2′)-β-D -glucopyranoside ( = anatolioside C; 4 ) and linalo-6-yl O-[(2E, 6R)-6-hydroxy-2,6-dimethylocta-2,7-dienoyl]-(1″? → 2″″)-O-β-D -glucopyranosly-(1″″ → 6?)-O-[(2E,6R)-6-hydroxy-2,6-dimethylocta-2,7-dienoyl]-(1? → 4″)-O-α-L -rhamnopyranosyl(1″ → 2′)-β-D -glucopyranoside ( = anatolioside D ; 5 ). The structure determinations were based on spectroscopic and chemical methods (acid and alkaline hydrolysis, acetylation and methylation).     

New saponins from Sechium mexicanum

The chemical study of Sechium mexicanum roots led to the isolation of the two new saponins {3‐O‐β‐D ‐glucopyranosyl (1 → 3)‐β‐D ‐glucopyranosyl‐2β,3β,16α,23‐tetrahydroxyolean‐12‐en‐28‐oic acid 28‐O‐α‐L ‐rhamnopyranosyl‐(1 → 3)‐β‐D ‐xylopyranosyl‐(1 → 4)‐α‐L ‐rhamnopyranosyl‐(1 → 2)‐α‐L ‐arabinopyranoside} (1) and {3‐O‐β‐D ‐glucopyranosyl (1 → 3)‐β‐D ‐glucopyranosyl‐2β,3β,16α,23‐tetrahydroxyolean‐12‐en‐28‐oic acid 28‐O‐α‐L ‐rhamnopyranosyl‐(1 → 3)‐β‐D ‐xylopyranosyl‐(1 → 4)‐[β‐D ‐apiosyl‐(1 → 3)]‐α‐L ‐rhamnopyranosyl‐(1 → 2)‐α‐L ‐arabinopyranoside} (2), together with the known compounds {3‐O‐β‐D ‐glucopyranosyl‐(1 → 3)‐β‐D ‐glucopyranosyl‐2β,3β,6β,16α,23‐pentahydroxyolean‐12‐en‐28‐oic acid 28‐O‐α‐L ‐rhamnopyranosyl‐(1 → 3)‐β‐D ‐xylopyranosyl‐(1 → 4)‐α‐L ‐rhamnopyranosyl‐(1 → 2)‐α‐L ‐arabinopyranoside} (3), tacacosides A₁ (4) and B₃ (5). The structures of saponins 1 and 2 were elucidated using a combination of ¹H and ¹³C 1D‐NMR, COSY, TOCSY, gHMBC and gHSQC 2D‐NMR, and FABMS of the natural compounds and their peracetylated derivates, as well as by chemical degradation. Compounds 1–3 are the first examples of saponins containing polygalacic and 16‐hydroxyprotobasic acids found in the genus Sechium, while 4 and 5, which had been characterized partially by NMR, are now characterized in detail. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis and biological activity of some new aminoacylcarbazole derivatives. Part I

The syntheses of different 9-(N-phthalyl- or N-tosyl- or free aminoacyl)carbazoles and the corresponding derivatives of 3,6-dinitrocarbazoles and some derivatives of 3,6-diamino-9-(N-phthalylaminoacyl)carbazoles (II-XXXII) are described. Compounds VIII, XIII-XVII and XXIII-XXVII were found to be active against a number of microorganisms.     

Synthesen des Analgetikums 2-[1-(m-Methoxyphenyl)-2-cyclohexen-1-yl]-N,N -dimethyl-äthylamin

Syntheses of the Analgesic 2-[1-(m-Methoxyphenyl)-2-cyclohexen-1-yl] -N,N-dimethyl-ethylamine Three principal routes to 2-[1-(m-methoxyphenyl)-2-cyclohexen-1-yl]- N,N-dimethyl-ethylamine (13) , a compound with interesting analgesic properties, are described. In the first, derivatives of [1-(m-methoxyphenyl)-2-cyclohexen-1-yl]acetic acid (10) (alternatively the ethyl ester 29 , the dimethylamide 32 or the nitrile 34 ) serve as crucial intermediates. All three can be synthesized from 2-(m-methoxyphenyl)cyclohexanone (1) by sequences comprising successively C-alkylation ( 1→2,4,5; Scheme 1), reduction of the ketone carbonyl group ( 2→6;4→18;5→19; Scheme 1 and 2) and elimination ( 16→29; 18→32; 19→34; Scheme 2). The relative configuration of the cyclohexanols 16, 18, 19 and of a series of related compounds is established by chemical correlation with the lactone 30 the structure of which follows from ¹H-NMR. data (Scheme 2). The second route creates the intermediates 29 and 32 by ester- or amide-enolate-Claisen-type-rearrangement reactions starting from 3-(m-methoxyphenyl)-2-cyclohexen-1-ol ( 39; Scheme 3). Compounds 29, 32 and 34 are transformed into the target molecule 13 by standard reactions. A Hofmann elimination of the quaternary ammonium fluoride 50 (X=F), derived from the known cis-perhydroindoline 48 , is the essential step in the third approach to 13 (Scheme 4).     

Photochemische Reaktionen. 97 Mitteilung [1]. Zur Photochemie konjugierter Epoxy-diene II. Versuche mit (E)-β-Jonyliden-epoxiden

Photolysis of Conjugated Epoxy-dienes Direct and sensitized excitation of the (E)-β-ionylidene-epoxides 1 and 4 leads to different types of isomerizations. Thus photocycloelimination to the cyclopropene-ketones 2 and 6 is only achieved by ¹(π, π*)-excitation (λ=254 nm), whereas ³(π, π*)-excitation (λ > 280 nm, acetone) gives selective C(1′), O-cleavage of the oxirane ( 1 → 7 – 10 and 4 → 11 – 13 ). In contrast to 1 the twofold methylsubstituted epoxy-diene 4 shows mainly (E/Z)-isomerization ( 4 → 5 ) on both ¹(π, π*)- and ³(π, π*)-excitation while the isomerizations 4 → 6 and 4 → 11 – 13 are minor processes, only.     

Spezifisch π→π*-induzierte Reaktionen von γ-Dimethoxymethylcyclohexen-2-onen: 1,3-Umlagerung und Wasserstoffabstraktion durch das α-Kohlenstoffatom

When α,β-unsaturated γ-dimethoxymethyl cyclohexenones are excited to the S₂(π,π*) state, certain unimolecular reactions can be observed to compete with S₂ → S₁ internal conversion. These reactions do not occur from the S₁(n,π*) or the lowest T(π,π* and n,π*) states. They comprise the radical elimination of the formylacetal substituent (cf. 8 , 9 → 32 + 33 ), γ → α formylacetal migration (cf. 6 → 27 , 8 → 30 , 9 → 34 , 12 → 37 ), and a cyclization process involving the transfer of a methoxyl hydrogen to the α carbon and ring closure at the β position (cf. 6 → 28 , 8 → 31 , 12 → 38 , 20 → 40 + 41 ). The quantum yield of the ring closure 20a → 40a + 41a is 0.016 at ≤ 0.05M concentration. It is independent of the excitation wavelength within the π→π* absorption band (238–254 nm), but Φ ( 40a + 41a ) decreases at higher concentrations. According to the experimental data the reactive species of these specifically π→π*-induced transformations is placed energetically higher than the S₁(n,π*) state, and it is either identical with the thermally equilibrated S₂(n,π*) state, or reached via this latter state. The linear dienone 14 undergoes a similar π→π*-induced cyclization (→ 42 ) whereas the benzohomologue 26 proved unreactive, and the dienone 22 at both n → π and π→π* excitation only gives rise to rearrangements generally characteristic of cross-conjugated cyclohexadienones.     

Synthesis of some 2-(N-protected or free aminoacyl or N-tosyltripeptide)-aminophenazines,aminonaphthophenazines and 4-(N-protected or free aminoacyl or N-tosyltripeptide)aminophenazone derivatives

The syntheses of different 2-(N-tosyl- or N-phthalyl- or free aminoacyl or N-tosyltripeptide)-aminophenazines, and the corresponding derivatives of 2-aminonaphthophenazines and some derivatives of 4-aminophenazones (IV-XXXIII) are described. Compounds XI-XIII, XX-XXIII, XXX-XXXII, XXXIV-XXXIX and XL-XLV were found to be active against a number of microorganisms.     

Synthesis of Tri-And Tetrasaccharides Present in the Linkage Region of Heparin and Heparan Sulphate

Abstract

The methyl glycosides of the the tri-and tetrasaccharides present in the linkage region of heparin, methyl O-(β-D-galactopyranosyl)-(l→3)-O-(β-D-galactopyranosyl)-(l→4)-β-D-xylopyranoside and methyl O-(β-D-glucopyranosyluronic acid)-(l→3)-O-(β-D-galactopyranosyl)-(l→3)-O-(β-D-galactopyranosyl)-(l→4)-β-D-xylopyranoside sodium salt, were synthesized together with their phosphate containing analogues, methyl O-(β-D-galactopyranosyl)-(l→3)-O-(β-D-galactopyranosyl)-(l→4)-β-D-xylopyranoside 2-(disodium phosphate) and methyl O-(β-D-glucopyranosyluronic acid)-(l→3)-O-(β-D-galactopyrano-syl)-(l→3)-O-(β-D-galactopyranosyl)-(l→4)-β-D-xylopyranoside 2-(disodium phosphate) sodium salt, which are glycosides of the structure found in the linkage region of heparan sulphate.     

Stereoselective Synthesis of a Tetrameric Fragment of Streptococcus Pneumoniae Type 1 Containing an α-Linked 2-Acetamido-4-amino-2,4,6-trideoxy-D-galactopyranose (SUGp) Unit

Abstract

Block condensation of fully protected donor ethyl 1,2,3,4-tetra-O-benzyl-D-Rib-(5→P→6)-2,3,4-tri-O-benzoyl-l-thio-β-D-Glcp (2), having a (5→6)-phosphotriester union between the ribitol and the glucopyranosyl moieties, with the free 3′-OH group in the acceptor methyl 2-acetamido-4-O-(2-acetamido-4-(benzyloxycarbonyl)amino-2,4,6-trideoxy-α-D-Galp)-3,6-di-O-benzyl-2-deoxy-α-D-Galp (3), under the agency of N-iodosuccinimide and triflic acid, gave the fully protected tetrameric fragment 22. Elimination of the 2-cyanoethyl group from the phosphotriester and subsequent debenzoylation, followed by hydrogenolysis of the benzyl and benzyloxycarbonyl groups provided the target tetramer methyl D-Rib-(5→P→6)-D-Glcp-β(1→3)-Sugp-α(1→4)-α-D-GalpNAc (1).     

New Triterpene Saponins from Herniaria glabra

Three new saponins 1–3 were isolated from Herniaria glabra by means of prep. HPLC and TLC. The structures were established mainly by a combination of 2D-NMR techniques (COSY, TOCSY, ROESY, HMQC, and HMBC) as O-α-L -rhamnopyranosyl-(1→4)-O-β-D -glucopyranosyl-(1-→6)-O-[β-D -glucopyranosyl-(1→2)]-β-D -glucopyranosyl medicagen-28-ate (herniaria saponin 4; 1 ), O-β-D -glucopyranosyl-(1→3)-O-α-L -rhamnopyranosyl-(1→2)-O-[β-(3R)-D -apiofuranosyl-(1→3)]-β-D -4-O-acetylfucopyranosyl 3-O-(β-D -glucuronopyranosyl)-16α-hydroxymedicagen-28-ate (herniaria saponin 5; 2 ), and O-α-L -rhamnopyranosyl-(1→4)-O-β-D -glucopyranosyl-(1→6)-O-[β-D -6-O-acetylglucopyra nosyl-(1→2)]-β-D -glucopyranosyl medicagen-28-ate (herniaria saponin 6; 3 ).     

Unusual Nortriterpenoid Saponins from Stauntonia chinensis

Four new saponins, yemuosides YM₁₇–YM₂₀ ( 1 – 4 , resp.), were isolated from the rattan of Stauntonia chinensis DC. (Lardizabalaceae) along with a known saponin, nipponoside D ( 5 ). Their structures were elucidated by spectroscopic analysis and chemical evidence as 20,30‐dihydroxy‐29‐noroleanolic acid 28‐O‐α‐L ‐rhamnopyranosyl‐(1→4)‐β‐D ‐glucopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl ester ( 1 ), 20,29‐dihydroxy‐30‐noroleanolic acid 28‐O‐α‐L ‐rhamnopyranosyl‐(1→4)‐β‐D ‐glucopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl ester ( 2 ), 29‐hydroxy‐30‐norolean‐20(21)‐enolic acid 28‐O‐α‐L ‐rhamnopyranosyl‐(1→4)‐β‐D ‐glucopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl ester ( 3 ), 29‐hydroxyoleanolic acid 28‐O‐α‐L ‐rhamnopyranosyl‐(1→4)‐β‐D ‐glucopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl ester ( 4 ), and 23,29‐dihydroxyoleanolic acid 28‐O‐α‐L ‐rhamnopyranosyl‐(1→4)‐β‐D ‐glucopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl ester ( 5 ). Yemuoside YM₁₇–YM₁₉ ( 1 – 3 , resp.) contain novel unusual nortriterpene aglycones.     

Doppelt und dreifach funktionalisierte,enantiomerenreine C4-Synthesebausteine aus β-Hydroxybuttersäure, Äpfelsäure und Weinsäure

Enantiomerically Pure Synthetic Building Blocks with Four C-Atoms and Two or Three Functional Groups from β-Hydroxy-butanoic, Malic, and Tartaric Acid The pool of chiral, non-racemic electrophilic building blocks, which are available from simple natural products in both enantiomeric forms is enlarged by the epoxides 3, 5 , and 10 , by the tosylate 12a , and by the aldehydes 18 (cf. symbols A-D , 14 , and Scheme 1). Key steps of the conversions leading from hydroxyacids to the building blocks are: epoxide-opening by triethylborohydride ( 1 → 2a ) and tosylate reduction ( 12a → 12b ); the Mitsunobu inversion ( 2a → 4a ); the reduction of (R, R)-tartaric ester to (R)-malic ester by NBS (N-bromosuccinimide) opening of the benzaldehyde acetal 8 and tin hydride reduction ( 6c → 7c ); the enantiomer enrichment of optically active ethyl β-hydroxy-butanoate through the crystalline dinitrobenzoate 21b . Detailed procedures are given for large scale preparations of the key intermediates. The enantiomeric purities of the building blocks are secured by correlations.     

Revised structures of avenacosides A and B and a new sulfated saponin from Avena sativa L.

The revised structures of avenacosides A and B and a new sulfated steroidal saponin isolated from grains of Avena sativa L. were elucidated. Their structures and complete NMR assignments are based on 1D and 2D NMR studies and identified as nuatigenin 3‐O‐{α‐l ‐rhamnopyranosyl‐(1→2)‐[β‐D‐glucopyranosyl‐(1→4)]‐β‐d ‐glucopyranoside}‐26‐O‐β‐d ‐glucopyranoside (1), nuatigenin 3‐O‐{α‐l ‐rhamnopyranosyl‐(1→2)‐[β‐d ‐glucopyranosyl‐(1→3)‐β‐d ‐glucopyranosyl‐(1→4)]‐β‐d ‐glucopyranoside}‐26‐O‐β‐d ‐glucopyranoside (2), and nuatigenin 3‐O‐{α‐l ‐rhamnopyranosyl‐(1→2)‐[β‐d ‐6‐O‐sulfoglucopyranosyl‐(1→4)]‐β‐d ‐glucopyranoside}‐26‐O‐β‐d ‐glucopyranoside (3). Copyright © 2012 John Wiley & Sons, Ltd.     

Structural characterisation of a water-soluble polysaccharide from tissue-cultured Dendrobium huoshanense C.Z. Tang et S.J. Cheng

A water-soluble polysaccharide TC-DHPA4 with a molecular weight of 8.0 × 10⁵ Da was isolated from tissue-cultured Dendrobium huoshanense by anion exchange and gel permeation chromatography. Monosaccharide analysis revealed that the homogeneous polysaccharide was made up of rhamnose, arabinose, mannose, glucose, galactose and glucuronic acid with a molar ratio of 1.28:1:1.67:4.71:10.43:1.42. The sugar residue sequence analysis based on the GC-MS files and NMR spectra indicated that the backbone of TC-DHPA4 consisted of the repeated units:→6)-β-Galp-(1→6)-β-Galp-(1→4)-β-GlcpA-(1→6)-β-Glcp-(1→6)-β-Glcp-(→. The sugar residue sequences β-Glcp-(1→)-α-Rhap-(1→3)-β-Galp-(1→, β-Glcp-(1→4)-α-Rhap-(1→3)-β-Galp-(1→, β-Galp-(1→6)-β-Manp-(1→3)-β-Galp-(1→, and α-l-Araf-(1→2)-β-Manp-(1→3)-β-Galp-(1→ were identified as the branches attached to the C-3 position of (1→6)-linked galactose in the backbone.     

Two new complex triterpenoid saponins from Gledistsia dolavayi Franch.

Two new triterpenoid saponins, gledistside A ( 1 ) and gledistside B ( 2 ), isolated from the fruits of Gledistsia dolavayi Franch., were characterized as the 3,28‐O‐bisdesmoside of echinocystic acid acylated with monoterpene carboxylic acids. On the basis of spectroscopic and chemical evidence, their structures were elucidated as 3‐O‐β‐D ‐xylopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl‐28‐O‐β‐D ‐xylopyranosyl‐(1→3)‐β‐D ‐xylopyranosyl‐(1→4)‐[β‐D ‐galactopyranosyl‐(1→2)]‐α‐L ‐rhamnopyranosyl‐(1→2)‐{6‐O‐[2,6‐dimethyl‐6(S)‐hydroxy‐2‐trans‐2,7‐octadienoyl]}‐β‐D ‐glucopyranosylechinocystic acid ( 1 ) and 3‐O‐β‐D ‐xylopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl‐28‐O‐β‐D ‐xylopyranosyl‐(1→3)‐β‐D ‐xylopyranosyl‐(1→4)‐[β‐D ‐galactopyranosyl‐(1→2)]‐α‐L ‐rhamnopyranosyl‐(1→2)‐{6‐O‐[2‐hydroxymethyl‐6‐methyl‐6(S)‐hydroxy‐2‐trans‐2,7‐octadienoyl]}‐β‐D ‐glucopyranosylechinocystic acid ( 2 ). The complete ¹H and ¹³C assignments of saponins 1 and 2 were achieved on the basis of 2D NMR spectra including HMQC‐TOCSY, TOCSY, ¹H–¹H COSY, HMBC, ROESY and HMQC spectra. Copyright © 2002 John Wiley & Sons, Ltd.     

1,4-Benzodiazepines III . Cyclization paths of hexaminium salts of 2-chioroacetamido-5-ehlorobenzophenone and its N-methyl derivative

This study reports the isolation and characterization of hexaminium salts of 2-chloroacetamido-5-chlorobenzophenone (I) and of 2-(N-methyl)chloroacetamido-5-chlorobenzophenone (II). The 7-chloro-1,3-dihydro-5-phenyl-2H-1,4-benzodiazepin-2-one (VI) and 7-chloro-1,3-dihydro-1-meth-yI-5-phenyl-2H-1,4-benzodiazepin-2-one (VII), respectively are of pharmacodynamic importance. Based on chromatographic separation of some intermediates, and on spectrophotometric monitoring of cyclizations I → VI and II → VII, respectively, two different pathways for these reactions have been proposed. Since the slowest step in the reaction sequence II → VII follows the quasi first order rate law, intramolecular nucleophilic attack of the benzophenone carbonyl group on the hexamine moiety proved to be decisive for the cyclization (scheme II). However, cyclization I → VI seems to incorporate quite different solvolytic pathways in addition to one corresponding to the sequence II → VII. Isolated 4-imidazolidinone intermediates N,N' -methylene-bis[3-{2 -benzoyl-4-chIoro)phenyI]-4-imidazolidinone(III), and 3-(2 -benzoyl-4′-chlorophenyI)-4-imidazolidinone hydrochloride (IV) recyclize into the 1,4-benzodiazepine VI. The optimal reaction conditions have been found to be between pH 6-7.     

Controlled Allylic Transformations via the Meisenheimer Rearrangement

Described are synthetic sequences which effect allylic transformations I and II. Sequence I involves (1) conversion of a primary allyl alcohol into the corresponding N, N-dimethyl-amine oxide, (2) [2,3]-rearrangement to give an N, N-dimethylhydroxylamine and (3a) reduction to give the ‘rearranged’ secondary or tertiary allyl alcohol [e.g. 36 → 35 → 37 → 40 ]. Sequence II involves the same steps (1) and (2), followed by (3b) N-methylation of a secondary N, N-dimethyl-hydroxylamine and (4) Hofmann elimination to give a vinyl ketone [e.g. 11 → 12 → 13 → 14 → 15 ].